Non-typhoidal Salmonella enterica serovars continue to be the leading cause of foodborne illnesses in United States. Chlorine, chlorine related, and quaternary compounds are generally used for disinfecting carcasses and equipment in processing industries. The current study was aimed at understanding the inactivation kinetics of four Salmonella serovars to chlorine, chlorine dioxide and cetylpyridinium chloride (CPC). The transcriptomic responses to oxidative stress was investigated in stationary and log phase cells of S. Typhimurium. The study was also aimed at understanding the effect of the chemicals on the expression of virulence genes associated with the Salmonella Pathogenecity Island 1 (SPI1). The possible induction of the viable but nonculturable (VBNC) state in Salmonella due to CPC was also investigated. The inactivation parameters for each serovar and the chemical were estimated based on the Hom's model, ln (N/N0) = -k C^n T^m and it appeared that while disinfectant contact time was significant, biocide concentration in the overall disinfection was insignificant. This was true especially for chlorine and CPC with subtle differences observed between the serovars. The inactivation efficacy was, however, dependent on both concentration and the exposure time for chlorine dioxide. The highest degree of inactivation was obtained with chlorine followed by chlorine dioxide and CPC. Transcriptomic responses of S. Typhimurium revealed significant downregulation of several metabolic processes such as tricarboxylic acid cycle, oxidative phosphorylation, and amino acid biosynthesis in both log and stationary phase cells. Several stress related genes such as usp, rpoS and ompR were upregulated in the stationary phase cells. Majority of the virulence genes associated with the SPI1 were found to be downregulated for all the treatments. While treatment with chlorine and CPC caused downregulation of all the virulence genes, treatment with chlorine dioxide caused significant upregulation of few (hilC, invC, sipA and sipB) genes associated with the SPI1. Finally, the induction of VBNC state was not concluded as a result of treatment with CPC. However, significant percentage of cells (45 percent) with intact membrane was established based on the BacLight assayTM.

Salmonella enterica Typhimurium is a common foodborne pathogen, and ready-to-eat (RTE) seafood is a potential source of Salmonella outbreaks. Lactic acid is a classical preservative in the meat industry and it is used with high efficacy to sanitize meat surfaces. Cetylpyridinium chloride (CPC) is a cationic quaternary ammonium compound proposed for use as a pathogen intervention substance. Cetylpyridinium chloride activity can be potentially affected by interactions between cetylpyridinium chloride and lactic acid. Lactic acid treatment (up to 1%) reduced Salmonella Typhimurium counts by less than 0.5 log cfu/g. Cetylpyridinium chloride treatment (up to 1%) reduced Salmonella Typhimurium counts by 0.9 log cfu/g. Cetylpyridinium chloride treatment at 18 and 45°C reduced populations of Salmonella Typhimurium by 1.34 and 1.14 log cfu/g. Combined treatment with cetylpyridinium chloride and lactic acid at 18 and 45°C decreased Salmonella Typhimurium counts by 0.83 log cfu/g and 1.05 log cfu/g. The single intervention of cetylpyridinium chloride was more effective than lactic acid used alone or combination of cetylpyridnium chloride and lactic acid to reduce Salmonella Typhimurium attached on ready-to-eat shrimp.

The purpose of this master thesis project was to investigate the penetration ofbiomolecules into hyaluronic acid (HA) macrogels. The investigations were performedboth in the presence and in the absence of the non-biodegradable surfactantcetylpyridinium chloride (CPC), which earlier has proved to form a micelle-rich shellat the gel surface. In this work investigations were performed to see if properties ofthe biomolecules used, such as size and charge, had any impact on the binding to theHA gels both with and without CPC. The biomolecules used were the proteinscytochrome c, lysozyme, hemoglobin and myoglobin and the polysaccharide dextranof different molecular weights and labeled with fluorescein isothiocyanate.Cetylpyridinium chloride was used as a non-biodegradable model surfactant for abiodegradable betaine ester surfactant. The cetylpyridinium chloride was thereforeserving well when performing control studies for the biodegradable betaine ester,because the two possesses similar properties. Investigations involving the betaineester surfactant was not included in this master thesis project. Also release studiesinvolving the labeled dextran and some of the proteins were performed in thepresence and absence of cetylpyridinium chloride.The binding of CPC to HA was investigated briefly as well as the microstructure ofHA gels saturated with CPC by means of small-angle X-ray scattering, SAXS, atdifferent salt concentrations. The microstructure-investigations indicated that at 10mM NaCl a cubic ordered phase with space group Pm3n was achieved. When the saltconcentration was increased to 40 mM the microstructure was altered to a clearface-centered cubic (FCC) structure. When increasing the NaCl concentrationfurther, to 150 mM, indication of an unordered micellar phase could be seen.Cytochrome c and lysozyme transport into HA gels, to which CPC had bound in anearlier step, could be registered using UV-VIS spectrophotometry. Indications showedthat CPC and cytochrome c was distributed to different parts of the gel frommicroscope pictures taken of the cross-section of gel samples at different time.From release experiments performed with fluorescein isothiocyanate-dextran noconclusions could be drawn on how the different molecular weights of dextranaffected the rate and extent of the amount substance released. Neither could theinfluence of CPC be elucidated. This since the extent of released amounts exceeded100 % for many samples and the duplicate samples investigated showed differentbehavior.The transport of cytochrome c, myoglobin and hemoglobin into HA gels with andwithout beforehand treatment with CPC was evaluated qualitatively. The transportinto gels treated with CPC was successful and complete with cytochrome c andmyoglobin at lower degree of binding but was limited for the bigger proteinhemoglobin. When investigating the release of cytochrome c, myoglobin andhemoglobin from HA gels the extent of released substance was lower with CPCpresent in the solution compared without CPC present. Also some indicationsshowed that the bigger size of hemoglobin affected the rate of release from the gel.

Since the surfaces of cantaloupes are highly rough or irregular, Salmonella enteric and other bacteria can easily attach to these surfaces and are difficult to remove. Cetylpyridinium chloride (CPC) is the active ingredient of some antiseptic oral mouth rinses and has a broad antimicrobial spectrum with a rapid bactericidal effect on Gram-positive pathogens. Delmopinol hydrochloride (delmopinol) is a cationic surfactant that is effective for treating and preventing gingivitis and periodontitis. The application of delmopinol or CPC to cantaloupe surfaces may be an alternative post harvest technique to reduce the frequency and level of Salmonella contamination. Cantaloupe (Athena and Hale's Best Jumbo (HBJ) cultivars) rind plugs were inoculated with a broth culture of Salmonella Michigan. After 15 min, plugs were sprayed with 10 ml of a 1% delmopinol solution, or a CPC solution (0.5 or 1.0%) or distilled water (Control), and held at 37 oC for 1 hr or 24 hr. For additional samples, the chemical treatments were applied 15 min before pathogen inoculation. Melon plugs were submerged in Butterfield's Phosphate Buffer, shaken, sonicated and solutions were enumerated on Tryptic Soy Agar. The texture quality and color of additional melon samples were evaluated after delmopinol or CPC spray treatments and storage at 4 oC. A 1.0% application of CPC reduced Salmonella levels up to 2.34 log CFU/ml (Athena) and 4.95 log CFU/ml (HBJ) in comparison to the control (p<0.01). A 1.0% delmopinol treatment reduced Salmonella levels as much as 3.1 log CFU/ml in comparison to the control (p<0.01) on both cultivars. In general, the log recovery of Salmonella on cantaloupes treated with delmopinol or CPC solutions, after 1 hr storage, was significantly lower (p<0.05) than the recovery from control cantaloupes, but Salmonella recovery was not significantly different after 24 hr. No significant differences were observed in the texture and color of melons treated with delmopinol or CPC after 14 days. A surface spray application of delmopinol hydrochloride or cetylpyridinium chloride could be an alternative antimicrobial post-harvest treatment that could make cantaloupes surfaces more susceptible to sanitizers or enhance physical removal of bacteria. / Ph. D.

Thesis (M.S.)--Mississippi State University. Department of Food Science Nutrition and Health Promotion. / Title from title screen. Includes bibliographical references.

Yes / We compared cetylpyridinium chloride (CPC), ethanol (ETOH), and OMNIgene.SPUTUM (OMNI) for 28-day storage of sputum at ambient temperature before molecular tuberculosis diagnostics. Three sputum samples were collected from each of 133 smear-positive tuberculosis (TB) patients (399 sputum samples). Each patient's sputum was stored with either CPC, ETOH, or OMNI for 28 days at ambient temperature, with subsequent rpoB amplification targeting a short fragment (81 bp, GeneXpert MTB/RIF [Xpert]) or a long fragment (1,764 bp, in-house nested PCR). For 36 patients, Xpert was also performed at baseline on all 108 fresh sputum samples. After the 28-day storage (D28), Xpert positivity did not significantly differ between storage methods. In contrast, higher positivity for rpoB nested PCR was obtained with OMNI (n = 125, 94%) than with ETOH (n = 114, 85.7%; P = 0.001). Smears with scanty acid-fast bacilli (AFB) had lower rpoB PCR positivity with ETOH storage (n = 10, 41.7%) than with CPC (n = 16, 66.7%; difference, 25%; 95% confidence interval [CI], 3.5 to 46.5; P = 0.031) or OMNI (n = 16, 69.6%; difference, 26.1%; 95% CI, 3.8 to 48.4; P = 0.031), with no difference between CPC and OMNI. Poststorage, the threshold cycle (CT ) values significantly decreased compared to those prestorage with ETOH (difference, -1.1; 95% CI, -1.6 to -0.6; P = 0.0001) but not with CPC (P = 0.915) or OMNI (P = 0.33). For one patient's ETOH- and CPC-stored specimens with a CT of <10, Xpert gave results of rifampin false resistant at D28, which was resolved by repeating Xpert on a 1/100 diluted specimen. In conclusion, 28-day storage of sputum in OMNI, CPC, or ETOH at ambient temperature does not impact short-fragment PCR (Xpert), including for low smear grades. However, for long-fragment PCR, ETOH yielded a lower PCR positivity for low smear grades, while the performance of OMNI and CPC was excellent for all smear grades. (The study has been registered at ClinicalTrials.gov under registration number NCT02744469.). / Directorate General for Development (DGD), Belgium (FA4 to C.N.S., B.C.D.J., D.A., and L.R.), and the European Research Council-INTERRUPTB starting grant (number 311725 to B.C.D.J., C.J.M., and L.R.)

A obtenção de pentóxido de vanádio mesoporoso, bem como a síntese, caracterização e estudo das propriedades de novos compostos híbridos, formado a partir do xerogel de pentóxido de vanádio e do pentóxido de vanádio mesoporoso, intercalados com espécies convidadas, foram os objetivos desta tese. O interesse nestes materiais, que apresentam uma considerável gama de modificações estruturais e químicas, é devido a possibilidade de arquitetar propriedades específicas e produzir novos materiais visando aplicações em óptica, catálise, dispositivos eletrônicos e sensores. Os compostos híbridos foram obtidos mediante a reação de intercalação utilizando espécies diretivas estruturais, como cloreto de cetilpiridínio, e materiais poliméricos, como óxido de polietileno e poli o-metoxianilina, introduzidos no interior do óxido em questão. O método de síntese é simples e relativamente rápido, uma vez que os materiais são obtidos em, no máximo, 10 dias, além de não ser necessário o monitoramento durante o período de preparação e secagem. Os resultados experimentais apontaram que houve uma expansão interplanar, bem como, as propriedades eletroquímicas dos compósitos apresentaram uma maior estabilidade de após vários ciclos quando comparados ao xerogel de pentóxido de vanádio, indicando uma reação de intercalação. Uma outra etapa deste trabalho foi à obtenção de óxido de vanádio mesoporoso. A formação de mesoporos foi confirmada pelas isotermas de adsorção/desorção. Em seguida, foi realizada a reação de intercalação com a introdução de óxido de polietileno e poli o-metoxianilina. A reação de intercalação utilizando esses polímeros na matriz mesoporosa proporcionou o aumento da mobilidade de íons lítio bem como um aumento na carga total, durante a reação redox, resultando num efeito sinérgico. Neste contexto, pode-se afirmar que, o método empregado mostrou-se extremamente atrativo devido a sua simplicidade de realização, além de possibilitar a obtenção de materiais com potencial aplicação como dispositivos eletroquímicos, baterias, e sensores químicos. / Synthesis, characterization of vanadium pentoxide mesoporous and studies of properties of hybrids compound based on vanadium oxide xerogel and vanadium pentoxide mesoporous, intercalated with guest species have been the main of this thesis. The interest in those materials, that present a considerable structural and chemical modification, is due to the possibility to tailor specific properties and produce new materials to application in optic, catalysis, electronic displays and sensors. The hybrid compounds were obtained from intercalation reaction utilizing templates agent such cetylpyridinium chloride and polymerics species such polyethylene oxide and poly o-methoxyaniline into the oxide. The synthesis is simple and relatively fast, and those materials are obtained, in a maximum, 10 days, even though it is not necessary the monitoring during the preparation and dry. The experimental results show an increase of interplanar, as well as, electrochemical properties of composites presented a better stability after several cycles as compared to vanadium pentoxide xerogel, indicating an intercalation reaction. Another stage of this work was to obtain the mesoporous vanadium pentoxide. The presence of porous was confirmed by adsorption isothermal method. Afterwards, it was realized the intercalation reaction with the polyethylene oxide and poly o-methoxyaniline into the matrix. The intercalation reaction using polymers into the porous matrix resulted an increase of Li+ ions mobility as well as an increase of total charge during the redox reaction resulting a synergic effect. In this context, it can be state that, the method used showed extremely attractive due to its simple synthesis, as well as it has the possibility of obtain materials with potential application such electrochemical displays, batteries and chemical sensors.

O antisséptico cloreto de cetilpiridíneo (CCP) demonstrou ser eficaz como alternativa terapêutica aos antifúngicos em candidose oral, porém, apresenta baixa substantividade. Para aumentar sua biodisponibilidade surge a possibilidade de incorporá-lo num sistema de liberação lenta composto por filmes poliméricos nanofibrílicos. O objetivo deste estudo foi preparar filmes nanofibrílicos através de eletrofiação e incorporar CCP, fazer sua caracterização térmica e morfológica, além de análise microbiológica dos filmes contendo CCP frente a cepas de Candida albicans. O fármaco CCP foi adicionado a três soluções poliméricas, de álcool polivinílico (PVA), polivinilpirrolidona (PVP) e a de PVP/PM [Poli (metacrilato de metila-co-acrilato de etila-co-metacrilato de amônio)] em 5% de concentração. As soluções foram avaliadas quanto à condutividade, viscosidade e tensão superficial e, posteriormente, passaram pelo processo de eletrofiação para obtenção de filmes nanofibrílicos. Os filmes nanofibrílicos foram caracterizados através de análise morfológica (microscopia eletrônica de varredura - MEV), análise térmica (análise termogravimétrica - TGA e calorimetria exploratória diferencial - DSC) e análise química (espectro de infravermelho da transformada de Fourier - FTIR). A eficiência de encapsulação de CCP nas nanofibras, o perfil cinético de liberação das nanofibras e a permeação em mucosa suína (células de Franz) foram avaliados por espectrofotometria. Foi ainda avaliada a concentração de CCP a ser incorporada (de 0,05 a 5%) em nanofibra para que a fração liberada seja a mínima fungicida frente às cepas de C. albicans susceptíveis, pela técnica de disco-difusão, comparada ao miconazol 5% (MCZ). Nestas condições, a solução de PVA apresentou a maior condutividade, viscosidade e tensão superficial. CCP aumentou a condutividade. Ambos, CCP e PM não alteram a tensão superficial do PVP. PM reduziu a viscosidade. A solução de PVP/PM formou o filme mais uniforme e com menos beads. Os termogramas (TGA/DSC) sugerem que o processo de eletrofiação diminiu a cristalinidade de CCP. A eficiência de encapsulação de CCP alcança 99%. A taxa de liberação de CCP encapsulado foi lenta durante o período experimental de 24h. Quando em filme nanofibrílicos, a atividade fungicida de CCP 2,5% e de MCZ 5% foi similar, mas somente MCZ foi fungistático. O filme nanofibrílico contrai em contato com o meio de cultura. Pode-se concluir que filmes nanofibrílicos de PVP/PM com CCP tem potencial para uso como alternativa para tratamento de infecções orais causadas por Candida. / The aim of this study was to prepare electrospun nanofiber films cetylpyridinium chloride (CPC) incorporated test their potential use as antifungal therapy against Candida albicans. CPC was incorporated to three different polymeric solutions, one containing polyvinyl alcohol (PVA), the second containing polyvinylpyrrolidone (PVP) and the third prepared with PVP and poly (methyl methacrylate-co-ethyl acrylate-co-methacrylate ammonium) (PMMA). These polymeric solutions were evaluated as to conductivity, viscosity and surface tension, then subjected to a electrospinning process to obtain nanofiber films. The morphology and structure of nanofiber films were analyzed using scanning electron microscopy (SEM). The characterization of nanofiber films was performed by thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). The encapsulation efficiency of the CPC nanofibers and the release kinetic profile of CPC and porcine mucosa permeation (Franz cells) were assessed by spectrophotometry. It was also assessed the concentration of CPC to be incorporated (from 0.05 to 5%) in nanofiber to be minimal fungicidal fraction released against strains of C. albicans by disk diffusion tests, compared to 5% miconazole (MCZ). Under these conditions, the PVA solution showed the highest conductivity, viscosity and surface tension. CPC increased conductivity. Both CPC and PMMA did not alter the surface tension of PVP. PMMA reduced viscosity. The solution of PVP/PMMA formed a more uniform film with less beads. Thermograms (TGA / DSC) suggested that the electrospinning process changes the crystallinity of CPC. The encapsulation efficiency reaches 99% of CPC. The release rate of encapsulated CPC was slow during the experimental period of 24 hours. In a nanofibrilic film, the fungicidal activity of CPC 2.5% and 5% MCZ was similar, but only MCZ proved fungistatic action. The nanofibrilic film shows contraction in contact with the culture medium. It can be concluded that nanofibrilic films PVP/PMMA with CPC has potential for use as an alternative for the treatment of oral infections caused by Candida.

A longevidade da prótese e a saúde bucal de usuário de Prótese Parcial Removível (PPR) são muito dependentes de higiene apropriada. O objetivo deste estudo foi comparar o efeito de soluções de Ricinus communis, em diferentes concentrações, com soluções de peróxido alcalino e cloreto de cetilpiridínio, em relação à liga metálica de Cobalto Cromo (Co-Cr) que compõe a estrutura de PPR. A amostra do experimento foi composta por 55 espécimes de Co-Cr, confeccionados a partir de padrões de cera circulares (12 mm x 3 mm) obtidos a partir de uma matriz metálica. Os padrões foram fundidos, numerados aleatoriamente e divididos em 5 grupos de imersão: H2O- água deionizada (controle) (15 minutos); Rc 2%- Ricinus communis 2% (20 minutos), Rc 10% -Ricinus communis 10% (20 minutos), PA- peróxido alcalino (15 minutos) e CCP- cloreto de cetilpiridínio 0,500 mg (10 minutos). Os espécimes foram avaliados quanto à rugosidade de superfície (n=10) no início e após a simulação de 6 meses, 1, 2, 3, 4 e 5 anos tanto pelo microscópio confocal a laser (Sa, &micro;m), como também pelo rugosímetro de superfície (Ra, &micro;m). Um espécime de cada grupo foi analisado quanto à topografia de superfície (Microscopia Eletrônica de Varredura, MEV) e Espectrometria de Energia Dispersiva de Raios-X (EDS) antes e após simulação de uso por 5 anos. De acordo com os resultados obtidos (&alpha;=0,05) pela microscopia confocal (Sa), não houve diferença para o fator solução (Kruskal-Wallis); para o fator tempo (Friedman) houve diferença estatística em Rc 2% entre T0 e T1, T3, T4 e T6 (p<0,001) e em Rc 10% de T2 para T3 (p=0,007), com diminuição da rugosidade. Com o rugosímetro (Ra), houve diferença estatística (Kruskal- Wallis) para CCP que apresentou menor rugosidade em relação à Rc 10% em T1 (p=0,048) e T6 (p=0,013). Em relação ao tempo (Friedman), a água propiciou diminuição da rugosidade superficial (Ra) de T0 para T2 (p=0,013). Na análise de MEV e EDS podese verificar que as soluções não apresentaram efeitos deletérios sobre as superfícies. Conclui-se que embora tenha sido encontrada diferença estatística para a rugosidade, os resultados são clínicamentes aceitáveis. Deste modo, todas as soluções podem ser utilizadas com segurança pelo período de 5 anos. / Denture longevity and oral health of Removable Partial Denture (RPD) user are highly dependent on proper hygiene. The aim of this study was to compare the effect of solutions of Ricinus communis, in different concentrations, with solutions of alkaline peroxide and cetylpyridinium chloride 0.500 mg, in relation to the Cobalt Chromium (Co-Cr) alloy that composes the structure of RPD. The sample of the experiment consisted of 55 specimens of Co-Cr, made from circular wax patterns (12 mm x 3 mm) obtained in a metal matrix. The patterns were cast, randomly enumerated and divided into 5 immersion groups: H2Odeionized water (control) (15 minutes); Rc 2%- Ricinus communis 2% (20 minutes), Rc 10% -Ricinus communis 10% (20 minutes), PA-alkaline peroxide (15 minutes) and CCPcetylpyridinium chloride 0.500 mg (10 minutes). The specimens were evaluated for surface roughness (n = 10) at the beginning and after the simulation of 6 months, 1, 2, 3, 4 and 5 years by the laser confocal microscope (Sa, &micro;m) and by the rugosimeter of surface (Ra, &micro;m). One specimen from each group was analyzed for surface topography (Scanning Electron Microscopy, SEM) and Energy-dispersive X-ray spectroscopy (EDS) befofe and after simulation of use for 5 years. According to the results obtained (&alpha;= 0.05) by confocal microscopy (Sa), there was no difference for the solution factor (Kruskal- Wallis); For the time factor (Friedman) there was a statistical difference in Rc 2% in T0 to T1, T3, T4 and T6 (p <0.001) and Rc 10% in T2 to T3 (p = 0.007), with decrease in roughness. With the the rugosimeter (Ra), there was a statistical difference (Kruskal- Wallis) for CCP that presented less roughness in relation to the Rc 10% in T1 (p = 0.048) and T6 (p = 0.013). In relation to the time, (Friedman) the water caused a reduction of surface roughness (Ra) between T0 and T2 (p = 0.013). In the analysis of SEM and EDS it can be verified that the solutions did not present deleterious effects on the surfaces. It was concluded that although a statistical difference was found for roughness, the results are clinically acceptable. Thus, all solutions can be safely used for a period of 5 years.

A longevidade da prótese e a saúde bucal de usuário de Prótese Parcial Removível (PPR) são muito dependentes de higiene apropriada. O objetivo deste estudo foi comparar o efeito de soluções de Ricinus communis, em diferentes concentrações, com soluções de peróxido alcalino e cloreto de cetilpiridínio, em relação à liga metálica de Cobalto Cromo (Co-Cr) que compõe a estrutura de PPR. A amostra do experimento foi composta por 55 espécimes de Co-Cr, confeccionados a partir de padrões de cera circulares (12 mm x 3 mm) obtidos a partir de uma matriz metálica. Os padrões foram fundidos, numerados aleatoriamente e divididos em 5 grupos de imersão: H2O- água deionizada (controle) (15 minutos); Rc 2%- Ricinus communis 2% (20 minutos), Rc 10% -Ricinus communis 10% (20 minutos), PA- peróxido alcalino (15 minutos) e CCP- cloreto de cetilpiridínio 0,500 mg (10 minutos). Os espécimes foram avaliados quanto à rugosidade de superfície (n=10) no início e após a simulação de 6 meses, 1, 2, 3, 4 e 5 anos tanto pelo microscópio confocal a laser (Sa, &micro;m), como também pelo rugosímetro de superfície (Ra, &micro;m). Um espécime de cada grupo foi analisado quanto à topografia de superfície (Microscopia Eletrônica de Varredura, MEV) e Espectrometria de Energia Dispersiva de Raios-X (EDS) antes e após simulação de uso por 5 anos. De acordo com os resultados obtidos (&alpha;=0,05) pela microscopia confocal (Sa), não houve diferença para o fator solução (Kruskal-Wallis); para o fator tempo (Friedman) houve diferença estatística em Rc 2% entre T0 e T1, T3, T4 e T6 (p<0,001) e em Rc 10% de T2 para T3 (p=0,007), com diminuição da rugosidade. Com o rugosímetro (Ra), houve diferença estatística (Kruskal- Wallis) para CCP que apresentou menor rugosidade em relação à Rc 10% em T1 (p=0,048) e T6 (p=0,013). Em relação ao tempo (Friedman), a água propiciou diminuição da rugosidade superficial (Ra) de T0 para T2 (p=0,013). Na análise de MEV e EDS podese verificar que as soluções não apresentaram efeitos deletérios sobre as superfícies. Conclui-se que embora tenha sido encontrada diferença estatística para a rugosidade, os resultados são clínicamentes aceitáveis. Deste modo, todas as soluções podem ser utilizadas com segurança pelo período de 5 anos. / Denture longevity and oral health of Removable Partial Denture (RPD) user are highly dependent on proper hygiene. The aim of this study was to compare the effect of solutions of Ricinus communis, in different concentrations, with solutions of alkaline peroxide and cetylpyridinium chloride 0.500 mg, in relation to the Cobalt Chromium (Co-Cr) alloy that composes the structure of RPD. The sample of the experiment consisted of 55 specimens of Co-Cr, made from circular wax patterns (12 mm x 3 mm) obtained in a metal matrix. The patterns were cast, randomly enumerated and divided into 5 immersion groups: H2Odeionized water (control) (15 minutes); Rc 2%- Ricinus communis 2% (20 minutes), Rc 10% -Ricinus communis 10% (20 minutes), PA-alkaline peroxide (15 minutes) and CCPcetylpyridinium chloride 0.500 mg (10 minutes). The specimens were evaluated for surface roughness (n = 10) at the beginning and after the simulation of 6 months, 1, 2, 3, 4 and 5 years by the laser confocal microscope (Sa, &micro;m) and by the rugosimeter of surface (Ra, &micro;m). One specimen from each group was analyzed for surface topography (Scanning Electron Microscopy, SEM) and Energy-dispersive X-ray spectroscopy (EDS) befofe and after simulation of use for 5 years. According to the results obtained (&alpha;= 0.05) by confocal microscopy (Sa), there was no difference for the solution factor (Kruskal- Wallis); For the time factor (Friedman) there was a statistical difference in Rc 2% in T0 to T1, T3, T4 and T6 (p <0.001) and Rc 10% in T2 to T3 (p = 0.007), with decrease in roughness. With the the rugosimeter (Ra), there was a statistical difference (Kruskal- Wallis) for CCP that presented less roughness in relation to the Rc 10% in T1 (p = 0.048) and T6 (p = 0.013). In relation to the time, (Friedman) the water caused a reduction of surface roughness (Ra) between T0 and T2 (p = 0.013). In the analysis of SEM and EDS it can be verified that the solutions did not present deleterious effects on the surfaces. It was concluded that although a statistical difference was found for roughness, the results are clinically acceptable. Thus, all solutions can be safely used for a period of 5 years.